The disclosure is significant because, while it has long been suspected that Mr Blair and his inner circle put pressure on Lord Goldsmith to change his legal advice, this is the first evidence that the PM actively blocked the Cabinet from hearing the full details of the case for war.
MPs from all parties urged Sir John Chilcot, who has finished taking evidence and is now preparing his report into the Iraq war, to reconvene a special session to hear from Mr Blair, Mr Campbell and Lord Goldsmith. The former Liberal Democrat leader Sir Menzies Campbell said: "According to the diaries, Tony Blair was determined that the decision should not rest with the Cabinet and overruled his Attorney General. Sofa government prevailed at the expense of constitutional requirements. The diaries prove that once a decision to go to war against Iraq had been taken, intelligence and legal advice was manipulated to support that decision."
Lord Goldsmith presented a longer legal opinion to Mr Blair on 7 March 2003 in which he said he believed there was a "reasonable case" in favour of military action, but that "there was also a case to be made the other way". According to Mr Campbell's diaries, Lord Goldsmith warned Mr Blair that he did not want the Prime Minister to "present it too positively" in favour of military action because there was a "case to be made the other way". Mr Campbell wrote: "TB also made it clear he did not particularly want Goldsmith to launch a detailed discussion at Cabinet, though it would have to happen at some time, and ministers would want to cross-examine. With the mood as it was, and with Robin [Cook] and Clare [Short] operating as they were, he knew if there was any nuance at all, they would be straight out saying the advice was that it was not legal, the AG was casting doubt on the legal basis for war. Peter Goldsmith was clear that though a lot depended on what happened, he was casting doubt in some circumstances and if Cabinet had to approve the policy of going to war, he had to be able to put the reality to them."
But Mr Campbell added that this was blocked by Mr Blair and his gatekeeper, Sally Morgan, during a meeting of Mr Blair and his closest aides on 11 March: "Sally said it was for TB to speak to Cabinet, and act on the AG's advice. He would simply say the advice said there was a reasonable case."
Following the 11 March meeting, Lord Goldsmith produced a new, one-page legal opinion which put the "reasonable case" for war – which was discussed at Cabinet and used in Parliament to justify military action.
In his own memoir, A Journey, Mr Blair did not reveal details of how he tried to block Lord Goldsmith. He said only that the Attorney General had "set out the arguments for and against and on balance came out in favour". When he gave evidence to the Chilcot inquiry in January 2010, Lord Goldsmith was asked by inquiry panel member Sir Roderic Lyne whether anyone asked him to "restrict what you said to Cabinet to the fairly limited terms in which you presented this to Cabinet". Lord Goldsmith replied: "No."
Sir Menzies added: "There seems to be a substantial difference between the contents of the diaries and the evidence given to the Chilcot inquiry, and the inquiry would be well advised to reconvene itself."
Last night Clare Short said she was not surprised that Mr Blair had been "deceitful" in presenting the case for war. Peter Kilfoyle, a minister in the Blair government, also called for the Chilcot inquiry to be recalled. "There is a straightforward contradiction between the two positions and it needs to be corroborated."
Blair's road to war
29 July 2002
Lord Goldsmith writes to Blair that regime change in Iraq is "not a legal basis for military action".
24 Sept 2002
"Dodgy dossier" in which Blair claims it is "beyond doubt" that Saddam has WMD.
22 Oct 2002
In submission to Chilcot, Lord Goldsmith says "my advice was not sought" after this date.